1. Field of Invention
The invention relates to a noiseless oil-free gas system for providing a high or low pressure gas to a pressure vessel.
2. Description of Prior Art
Conventional gas compressors are generally piston driven devices in which the gas to be compressed is injected into the compression chamber and then a piston moving in a cylinder compresses the gas. The high-pressure gas is vented to a storage container or another compression stage and additional gas is injected into the compression chamber. Such pumps are generally very noisy as a result of the moving piston and the alternating opening and closing of the inlet/outlet valves producing a pulsating source of compressed gas. Such noise is very undesirable in most military submersible vehicles. Further, lubricating oil along the cylinder wall contaminates the compressed gas in most systems such that the high pressure air is not breathable. Multi-stage devices, or those yielding oil-free compressed gas, are still noisy and are generally large, complex and require high levels of maintenance. Similar limitations exist in conventional vacuum pumps. Other prior art devices which have storage reservoirs containing a liquid and a gas under pressure usually require some compensating mechanism to adjust for the gas absorbed by the liquid when under pressure in order to maintain the device at a desired operational state. The present device can convert a low-pressure gas to a high-pressure one or vice versa in a virtually noiseless, continuous, single operation. Further, the gas so produced is oil-free and no compensating mechanism is required to adjust for any gas absorbed by the liquid.